trick for marathon for running docker + weave

weave DNS trick

a little trick with weave and marathon is the specification of the hostname.  unlike raw docker+weave, the hostname in weave DNS can be picked up by --name or --hostname.  But with the marathon json, hostname must have .weave.local as a suffix.  so, to deploy postgres via marathon and give it a weave DNS entry of postgres-server, the entry needs to be postures-server.weave.local